[dpdk-stable] vhost: many vhost user ports (backporting to v16.11)

[Yuanhan Liu]

On Thu, Feb 09, 2017 at 07:56:29AM -0500, Robert Wojciechowicz wrote:
> Hi,
> 
> in DPDK v17.02-rc2 there is available following patch:
> 
> commit: 59317cef249c0b23098543df527b3e360ce9764f
> 
> """
> vhost: allow many vhost-user ports
> Currently select() is used to monitor file descriptors for vhostuser
> ports. This limits the number of ports possible to create since the
> fd number is used as index in the fd_set and we have seen fds > 1023.
> This patch changes select() to poll(). This way we can keep an
> packed (pollfd) array for the fds, e.g. as many fds as the size of
> the array.
> Also see:
> http://dpdk.org/ml/archives/dev/2016-April/037024.html
> Reported-by: Patrik Andersson <patrik.r.andersson at ericsson.com>
> Signed-off-by: Jan Wickbom <jan.wickbom at ericsson.com>
> Signed-off-by: Yuanhan Liu <yuanhan.liu at linux.intel.com>
> """
> 
> I tested this feature with OVS and DPDK v17.02-rc2.
> I applied also this patch to DPDK v16.11 without any issues
> and performed the same tests as for v17.02-rc2.
> It solves the problem with connecting many VMs to one vSwitch
> instance (in my tests 70 VMs) with vhost user ports.
> 
> Is it possible to backport this feature to DPDK v16.11?

As a vhost maintainer, I think this patch could be backported to v16.11:
it resolves an issue you met.

Just let me know if anyone has objections.

> It is also worth pointing out that OVS 2.7 will use 16.11 

One question though: will they use v16.11.1 or something like that?

	--yliu

> which means we will have this bug for the next 6 months at least 
> unless we can backport.
> 
> What's your opinion?
> 
> Br,
> Robert